Apparatus for dispersing finely divided solid particles in a liquid vehicle

ABSTRACT

Apparatus for dispersing finely divided solid particles in a liquid vehicle including a mixing vessel comprising one or more dish-shaped elements which may be easily removed from each other and assembled to each other and which in their assembled relationship provide one or more chambers wherein a fluid mixture is agitated and subjected to high pressures in the process of finely dividing solid particles and effecting distribution in the liquid vehicle.

iJnite States Patent 1191 Schold Nov. 5, 1974 APPARATUS FOR DISPERSINGFINELY 3,009,685 ll/l96l Rettig 259/7 223%; PARTICLES IN A LIQUIDFOREIGN PATENTS OR APPLICATIONS 661,707 7 4/1963 Canada 259/7 [76]inventor: George R. Schold, 7909 2nd St. N.,

Petersburg, 33702 Primary Examiner-Harvey C. Hornsby [22] Filed: Sept.27, 1972 Assistant Examiner-Philip R. Coe

[21] 1 Appl. No: 292,801 [57] ABSTRACT Apparatus for dispersing finelydivided solid particles 2% 259/8 259/DIG' a q i in a liquid vehicleincluding a mixing vessel compris- DIG ing one or more dish-shapedelements which may be 1 Bare easily removed from each other andassembled to 56 R f d each other and which in their assembledrelationship 1 e erences provide one or more chambers wherein a fluidmixture UNITED STATES PATENTS is agitated and subjected to highpressures in the pro- 1,030,203 6/1912 Paulsen 259/8 X cess of finelydividing solid particles and effecting dis- ;gfigg; gi k ti tribution inthe liquid vehicle.

0 er y 2,929,107 3/1960 Andrew 259/7 X 9 Clams, 8 Drawlng Flgllrss 4621; 118 50 3 g: f .96 A 23 51- \l 22 6762 1 8 5 -25 5 I 3 '65 arc l 1;27 -32 3Z i 37 267;; q 5 53 1 PATENTEUNnv 51974 sum 4 3,845,938

PATENTEDNUV 5 mm I SHEEF 2 [IF aieasm APPARATUS FOR DISPERSING FINELYDIVIDED SOLID PARTICLES IN A LIQUID VEHICLE BACKGROUND OF THE INVENTIONThis invention relates to an apparatus for dispersing finely dividedparticles in a liquid vehicle.

In the manufacture of products such as paints, enamels, inks and dyes,the solid material ingredient of the product is usually introduced intothe liquid vehicle in a finely divided form having a particle size aslow as one micron. Such solid particles are substantially insoluble andinert with respect to the liquid vehicle and when such material is firstintroduced into the liquid vehicle the particles tend to form lumpswhich are an agglomeration of a multitude of particles surrounded by afilm of the liquid vehicle. As a result, the outermost surfaces of manyof the particles agglomerated in each lump remain dry and do not readilydisperse uniformly in the liquid vehicle. Further background on theproblems involved and the apparatus previously used in dispersing suchparticles in a liquid vehicle are discussed in my US. Pat. No. 3,488,009for Means and Method for Dispersing Finely Divided Solid Particles in aLiquid Vehicle issued Jan. 6, I970.

The apparatus disclosed herein is designed to perform substantially thesame function as the apparatus described in my above referred to U.S.Pat. No. 3,488,009. The apparatus disclosed herein, however, is animproved structure. Just as in the apparatus of my US. Pat. No.3,488,009, the apparatus herein described may be used for uniformlydistributing finely divided particles in a liquid vehicle without theneed of a dispersing agent. The apparatus described herein has beenfound particularly useful in the processing of dye materials. One of theproblems that has been experienced in apparatus of this kind is that inprocessing certain materials such as some dyes, for example, atremendous amount of heat is generated in the mixing vessel. A normaltype of cooling jacket wherein coolant is circulated around the outsidewall of the mixing vessel has been found insufficient in processingcertain materials to hold down the temperature of the vessel structurewithin desired limits. For that reason other means had to be developedwhich would provide more adequate cooling.

SUMMARY OF THE INVENTION Briefly, the apparatus described hereinincludes a vessel into which extends a rotatable shaft on which aremounted one or more agitator discs. The vessel is constructed to includeone or more annular dish-shaped elements superimposed one upon theother. If a plurality of dish-shaped elements are used they are stackedone upon the other to thereby define annular chambers into which theagitator discs extend. If only one dishshaped element is used, then thatdish-shaped element together with an end plate defines an annularchamber into which an agitator disc extends. An inlet is provided at oneend of the vessel and an outlet at the other for the fluid mixture beingprocessed. The dish-shaped elements are individually formed withinternal chambers through which heat controlling fluid usually forcooling is circulated during operation of the apparatus.

A principal object of the present invention is to provide a mixingvessel of such a construction as to allow 2 for a more efficienttemperature control of the product being processed.

A still further object of the inventionv is to provide a mixing vesselincluding dish-shaped elements formed with internal cavities or passagesfor'circulating temperature control fluid therethrough whereby thetemperature of the mixing vessel apparatus may be easily controlled.

Another object of the invention is to provide means for constructingmixing vessels whereby different sizes of mixing vessels may be easilymanufactured without changing the basic structure of the entire unit.

A further object of the invention is to provide an apparatus wherein themixing vessel comprises a plurality of dish-shaped elements which may beeasily assembled or removed from each other.

Other objects and advantages of the invention herein will become moreapparent when the description is considered in connection with theaccompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view in elevation of theapparatus embodying the invention herein;

FIG. 2 is a side view in elevation of the apparatus of FIG. 1;

FIG. 3 is an enlarged view in elevation of the mixing vessel assembly,shaft and agitator discs;

FIG. 4 is a view in elevation of one of the dish-shaped elements used inthe mixing vessel assembly,

FIG. 5 is a top view of the dish-shaped element of FIG. 4;

FIG. 6 is a plan view of one of the agitator discs used in theapparatus;

FIG. 7 is an enlarged view in perspective of the circled portion of theagitator disc of FIG. 6;

FIG. 8 is a view in elevation of a mixing vessel utilizing only onedish-shaped element.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsFIGS. 1 and 2 show the overall dispersing apparatus 10 including a base11, a vertical support 12 mounted on the base 11, a motor 13 and a beltand pulley drive unit 14 mounted on the vertical support for drivingashaft 15 which extends into a vertically disposed mixing vessel assembly16. Product to be processed is introduced into the mixing vessel 16under pressure through an inlet 17 via a conduit 20. The conduit isconnected to a pump 21 which is adapted to take a suction from a tank(not shown) containing the material to be processed. The shaft 15 whichextends into the mixing vessel 16 carries one or more agitator discs 22.

The mixing vessel assembly 16 shown in FIG. 3 comprises one or moreannular dish-shaped elements 23, end plates 24 and 25 disposed at eachend of the vessel and a plurality of tie rods 26 extending through theend plates 24 and 25 to hold the end plates and dish-shaped elements inassembled relationship. Each annular dishshaped element 23 is of asubstantially U-shaped crosssection and has a horizontally extendingbase portion 27 and a wall portion 30 extending at substantially rightangles to and connected to said base portion.

In order to accomplish more effective temperature control of the mixingvessel apparatus each dish-shaped element 23 is formed with an internalcavity or passage 32. This cavity or passage 32 has a horizontal portion32a and a vertical or axially extending portion 32b generallyparalleling the base portion 27 and wall portion 30 respectively. Acoolant, such as water may be circulated through the cavity or passage.The lower surface of the base portion 27 has a cut-out portion 33 formedtherein for receiving therein the upper end of the wall portion 30 ofthe next adjacent dish-shaped element. A plurality of inlet passages 34are formed in this cut-out portion of the base portion which function ascoolant inlets. It will be observed that these passages 34 are disposedat an inwardly directed angle and are effective to direct fluid into thehorizontal portion of the passage as viewed in FIG. 3 for example toimprove circulation throughout the element 23.

The upper surface 35 of the wall portion 30 has a plurality ofcircumferentially spaced outlet passages 36 and an annular fluid passageor groove 37 formed therein, the outlet passages 36 being in fluidcommunication with the annular groove 37 and the internal cavity 32. Theupper surface 35 also has a pair of annular radially spaced seal grooves40 and 41 formed therein for accommodating O-ring seals 42 and 43. Inthe assembly, the O-ring seals 42 and 43 are disposed radially on eachside of the annular groove 37 to prevent leakage of fluid along thesurface 35 which fits into the cut out portion 33 in the base of theadjacent dish-shaped element. Each dish-shaped element also is formedwith a central opening 38 through which the shaft extends in theassembly, the opening 38 being considerably larger than the diameter ofspacers used to separate agitator discs on the shaft 15.

In the assembly a coolant inlet 44 is formed in the end plate and isadapted to be connected to a source of coolant through conduit 45. Theinlet 45, of course, communicates with the internal cavity 32 in thedishshaped element 23 through the passages 34 formed in the base portion27. A coolant outlet 46 is formed in the end plate 24 and is adaptedtohave an outlet conduit 47 connected thereto. An outlet 48 for theprocessed product is provided in end plate 24.

The agitator disc 22 is formed of solid metal. The agitator disc blankoriginally has a finished thickness at its outer periphery substantiallyas indicated by the dimension 50. During the manufacturing process, apair of axially spaced peripheral grooves 51 and 52 are cut in theperiphery to a desired depth. This leaves very thin blade sectionsformed at the outer extremities of opposed flat sides of the disc and acentral core portion 53. Then a plurality of radially extending slits 54are cut in the thin sections at each side of the disc. This leaves aplurality of circumferentially spaced segments which at that stage, ofcourse, all lie in a plane normal to the axis of the disc. Each of thesesegments are then twisted to a predetermined angle out of the planenormal to the axis of the disc resulting in the vanes 55 as shown inFIGS. 3 and 8 having leading edges 56. The vanes 55 on opposite sides ofthe core portion 53 are twisted in opposite directions and generally anequal amount. A central opening 57 is provided in the disc to receivethe shaft 15 therethrough the disc then being keyed to the shaft.

In the assembly the shaft 15 is driven by motor 13 through belt andpulley arrangement 14 and is positioned in a housing 58 by suitableupper and lower bearing means 60 and 61. The housing 58 is attached toor may be constructed integral with the end plate 24.

4v The shaft 15 extends into the mixing assembly and carries thereon theagitator discs 22 separated by spacers 62. The entire shaft and discassembly are secured together by suitable means, such as a nut 63attached to the threaded end of shaft 15.

The dish-shaped elements being adjacently disposed and stacked one uponthe other provide circumferential chambers 64 (shown as 64a, 64b and 64:in FIG. 3) into which the agitator discs 22 extend. It will be observedthat the outer edges of the discs 22, more specifically the outerperipheral axially extending surfaces 65 of the central core portion 53,are relatively closely spaced from the inner surface 66 of the wallportions 30 of each of the dish-shaped elements. This close spacingprovides an annular pressure zone 67 (shown as 67a, 67b and 670 in FIG.3) through which all product being processed must pass as explained inmy US. Pat. No. 3,488,009. The spacing may vary between approximatelyten and one hundred thousandths of an inch depending on the materialbeing processed, about twenty-five thousandths of an inch having beenfound to be a preferable spacing when used on some products. Annularopenings or passages 70 are provided by the space between the shaftspacers 62 and the enlarged central openings 38 in the dish-shapedelements. The path of flow of product through the mixing vessel assemblyis indicated by arrows 68.

In view of the path of flow of the material it can readily be seen thatthe construction of the dish-shaped elements 23 with their internalfluid passages 32 provides a greater cooling area for the product beingprocessed.

OPERATION The operation which should be apparent from the abovestructural description can be briefly described as follows: Rotation ofthe shaft 15 with attached agitator discs 22 is accomplished by the beltand pulley drive 14 from the motor 13. The shaft is rotated in clockwisedirection when viewed from the top down as seen in FIG. 3. The speed ofthe motor 13 and consequently the shaft may be controlled by a varietyof means not shown herein. A fluid mixture including a liquid vehiclesuch as an oil together with agglomerated particles of undispersedsolids such as a pigment is introduced through inlet 17 by means of thepump 21 through conduit 20. The pump 21 supplies the materialcontinuously to chamber 71 of the mixing vessel building up a pressureup to a predetermined pressure and which is slightly higher than thepressure at the pressure zones 67. Thus the mixture under pressure iscontinuously forced through the chambers 64a, pressure zone 67a, chamber64b, pressure zone 67b, chamber 64c and pressure zone 67c and theassociated passages 70 between the shaft spacers 62 and the opening 38in the dish-shaped elements to the outlet 48.

As this occurs, the lumps of solid particles are torn apart andprogressively reduced in size by the abrading action of the fast movingroughened anvil surfaces 65 on the agitator discs. Agitation also occursthroughout the stream of fluid mixture which further assists in breakingup the solid particles. In passing through the mixing vessel assemblyand particularly zones 67 the substantial pressures to which the fluidmixture is subjected generates a substantial amount of heat, which mayvary, of course, with the particular material being processed. Tocontrol the temperature to which the mixing vessel is subjected,temperature control fluid such as water is injected at inlet 45 andcirculated through each of the dish-shaped elements 23 to the outlet 46.The fluid enters the first element 23, through passages 34, movesthrough the internal passageway 32 to the outlets 36 to the circularoutlet groove 37 then into the fluid inlets 34 of the next adjacentdish-shaped element 23'and then successively through each of thedish-shaped elements 23 to outlet 46 in the end plate 24. Under certaincircumstances it is conceivable that the circulating fluid may be run inthe opposite direction, i.e. from top to bottom into outlet 46 and outthe inlet 45. The fluid circulation provided by the unique internalpassage construction of the dish-shaped elements has been able toachieve overall cooling of the mixing vessel assembly to a degreepreviously not obtainable with a simple straight cooling jacketsurrounding the outside wall of the vessel.

Mixing vessels of various sizes may be constructed merely by using moreor less than three dish-shaped elements 23 in the assembly. This, ofcourse, will dictate the use of correspondingly longer or shorter shaftsto accommodate a greater or lesser number of agitator discs 22. Such amodified version of a mixing vessel is shown in FIG. 8. It operates insubstantially the same manner as the unitshown in FIG. 3, the onlydifference being that only one dish-shaped element 15 and one agitatordisc 22 are used.

Using dish-shaped elements 23 to construct a mixing vessel provides .atremendous manufacturing convenience in the sense that large or smallermixing vessels may be easily constructed without changing the basicstructureof the unit as a whole. Different length shafts are easilyprovided using a greater or lesser number of the same type agitatordiscs as needed. a The structure of the mixing vessel also greatlyfacilitates repair. If one portion is worn it is necessary to replaceonly a portion thereof namely one or more of the dish-shaped elements.

It will be apparent that l have advantageously provided a mixing vesselfor incorporation in the apparatus described of a type which gives agreat deal of flexibility in the manufacture and repair.

' Furthermore, the mixing vessel is of such a construction as to includean improved temperature control means by providing greater surface areaover which the temperature controlling fluid can act.

While a preferred embodiment of the invention has been specificallydisclosed, it is to be understood that the invention is not limitedthereto as other variations will be apparent to those skilled in the artand the invention is to be given its fullest possible interpretationwithin the terms of the following claims.

I claim:

1. Apparatus for dispersing solid particles held in agglomerated formand carried in suspension by a liquid vehicle as a fluid mixturecomprising:

a mixing vessel having a fluid inlet at one end thereof and a fluidoutlet at the other end thereof. said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture through said mixingvessel to said outlet;

said vessel comprising a plurality of annular dishshaped elements havinga substantially U-shaped cross section and stacked one upon the other,and closure means associated with said dish-shaped ele- 6 mentsenclosing said vessel at both ends, each of said dish-shaped elementscomprising a laterally extending base portion and an axially extendingwall portion connected to said base portion; releasable means holdingsaid dish-shaped elements and said closure means in assembledrelationship;

said dish-shaped elements in their assembled relationship definingcircumferentially extending chamber means thcrebetween;

means defining internal fluid cavities in each of said dish-shapedelements for conducting temperature control fluid therethrough;

communicating passage means in said dish-shaped elements connecting theinternal cavities of each of said dish-shaped elements with each other;

a rotatable shaft extending into said vessel through said dish-shapedelements and adapted to be driven from a power source; and

agitator disc means mounted on said shaft and projecting radially intosaid chamber means.

2. The apparatus of claim 1 wherein said communicating passage meansincludes a continuous annular passageway in the upper face of saiddish-shaped element for communicating with inlet ports formed in thebase of anfiadjacent dishshaped element.

3. Apparatus for dispersing solid particles held in agglomerated formand carried in suspension by a liquid vehicle as a fluid mixturecomprising:

a mixing vessel having a fluid inlet at one end thereof and a fluidoutlet at the other end thereof, said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture through said mixingvessel to said outlet;

said vessel comprising a plurality of annular dishshaped elements havinga substantially U-shaped cross section and stacked one upon the other,and closure means associated with said dish-shaped elements enclosingsaid vessel at both ends, each of said dish-shaped elements comprising alaterally extending base portion and an axially extending wall portionconnected to said base portion;

releasable means holding said dish-shaped elements and said closuremeans in assembled relationship;

said dish-shaped elements in their assembled relationship definingcircumferentially extending chamber means therebetween;

a rotatable shaft extending into said vessel through said dish-shapedelements and adapted to be driven from a power source;

agitator disc means mounted on said shaft and projecting radially intosaid chamber means; and

said agitator disc means is an integral disc including a central bodyportion and integral radially extending blade portions disposed on eachside of and axially spaced from said central body portion and vane meansformed in each of said blade portions.

4. Apparatus for dispersing solid particles held in agglomerated formand carried in suspension by a liquid vehicle as a fluid mixturecomprising:

a mixing vessel having a fluid inlet at one end thereof and a fluidoutlet at the other end thereof, said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture under pressurethrough said mixing vessel to said outlet;

said mixing vessel including at least one annular dishshaped elementhaving a substantially radially extending base portion and asubstantially axially ex tending flange portion connected to saidradially extending base portion and a closure member covering saiddish-shaped element to define with the latter an annular chamber;

releasable means securing said dish-shaped element and said closuremember in assembled relationship whereby said dish-shaped element andclosure member may be easily assembled and disassembled;

a rotatable shaft extending into said vessel;

an agitator disc secured to said shaft and extending into said annularchamber, said agitator disc being an integral disc including a centralbody portion and integral radially extending blade portions disposed oneach side of and axially spaced from said central body portion and vanemeans formed in each of said body portions;

means defining completely circumferentially extending internal fluidpassage means in both said base portion and said flange portion of saiddish-shaped element for conducting temperature control fluidtherethrough; and

fluid inlet and outlet means to said internal fluid passage means.

5. Apparatus for dispersing solid particles held in agglomerated formand carried in suspension by a liquid vehicle as a fluid mixturecomprising:

a mixing vessel having a fluid inlet at one end thereof and a fluidoutlet at the other end thereof, said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture through said mixingvessel to said outlet;

said vessel comprising a plurality of annular dishshaped elementsstacked one upon the other and closure means associated with saiddish-shaped elements enclosing said vessel at both ends;

releasable means holding said dish-shaped elements and said closuremeans in assembled relationship;

said dish-shaped elements in their assembled relationship definingcircumferentially extending chamber means therebetween;

means defining separate completely circumferentially extending internalfluid cavities entirely within each of said dish-shaped elements forconducting temperature control fluid therethrough;

communicating passage means in said dish-shaped elements connecting theinternal cavities of each of said dish-shaped cavities with each other;

a rotatable shaft extending into said vessel through said dish-shapedelements and adapted to be driven from a power source; and

agitator disc means mounted on said shaft and projecting radially intosaid chamber means.

6. The apparatus of claim wherein,

said communicating passage means includes a continuous annularpassageway in the upper face of said dish-shaped element forcommunicating with inlet ports formed in the base of an adjacentdishshaped element.

7. Apparatus for dispersing solid particles held in agglomerated formand carried in suspension by a liquid vehicle as a fluid mixturecomprising:

a mixing vessel having a fluid inlet at one end thereof and a fluidoutlet at the other end thereof, said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture through said mixingvessel to said outlet;

said vessel comprising a plurality of annular dishshaped elementsstacked one upon the other and closure means associated with saiddish-shaped elements enclosing said vessel at both ends;

releasable means holding said dish-shaped elements and said closuremeans in assembled relationship;

said dish shaped elements in their assembled relationship definingcircumferentially extending chamber means therebetween;

means defining separate completely circumferentially extending internalfluid cavities entirely within each of said dish-shaped elements forconducting temperature control fluid therethrough;

a rotatable shaft extending into said vessel through said dish-shapedelements and adapted to be driven from a power source;

agitator disc means mounted on said shaft and projecting radially intosaid chamber means; and

said agitator disc being an integral disc including a central bodyportion and integral radially extending blade portions disposed on eachside of and axially spaced from said central body portion and vane meansformed in each of said body portions.

8. ln a closed mixing vessel apparatus for dispersing solid particlesheld in agglomerated form and carried in suspension by a liquid vehicleas a fluid mixture, said mixing vessel having a chamber in which anagitator disc adapted to be rotated is disposed, the combinationcomprising:

an integral agitator disc including a central body portion, and integralradially extending blade portions disposed on each side of and axiallyspaced from said central body portion and at the outer periphery of saiddisc; and

vane means formed in each of said blade portions.

9. The combination of claim 8 wherein,

said agitator disc member is of substantial thickness being formed withtop and bottom faces and includes means defining a pair of radiallydirected circumferentially extending slots disposed in substantiallyparallel relationship and formed in the periphery of said agitator disc,said slot means defining said blade portions at the outer edge of and asan integral part of said top and bottom faces, said slot means furtherdefining said central body portion disposed between and axially spacedfrom said blade portions.

1. Apparatus for dispersing solid particles held in agglomerated formand carried in suspension by a liquid vehicle as a fluid mixturecomprising: a mixing vessel having a fluid inlet at one end thereof anda fluid outlet at the other end thereof, said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture through said mixingvessel to said outlet; said vessel comprising a plurality of annulardish-shaped elements having a substantially U-shaped cross section andstacked one upon the other, and closure means associated with saiddish-shaped elements enclosing said vessel at both ends, each of saiddish-shaped elements comprising a laterally extending base portion andan axially extending wall portion connected to said base portion;releasable means holding said dish-shaped elements and said closuremeans in assembled relationship; said dish-shaped elements in theirassembled relationship defining circumferentially extending chambermeans therebetween; means defining internal fluid cavities in each ofsaid dishshaped elements for conducting temperature control fluidtherethrough; communicating passage means in said dish-shaped elementsconnecting the internal cavities of each of said dish-shaped elementswith each other; a rotatable shaft extending into said vessel throughsaid dishshaped elements and adapted to be driven from a power source;and agitator disc means mounted on said shaft and projecting radiallyinto said chamber means.
 2. The apparatus of claim 1 wherein saidcommunicating passage means includes a continuous annular passageway inthe upper face of said dish-shaped element for communicating with inletports formed in the base of an adjacent dish-shaped element. 3.Apparatus for dispersing solid particles held in agglomerated form andcarried in suspension by a liquid vehicle as a fluid mixture comprising:a mixing vessel having a fluid inlet at one end thereof and a fluidoutlet at the other end thereof, said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture through said mixingvessel to said outlet; said vessel comprising a plurality of annulardish-shaped elements having a substantially U-shaped cross section andstacked one upon the other, and closure means associated with saiddish-shaped elements enclosing said vessel at both ends, each of saiddish-shaped elements comprising a laterally extending base portion andan axially extending wall portion connected to said base portion;releasable means holding said dish-shaped elements and said closuremeans in assembled reLationship; said dish-shaped elements in theirassembled relationship defining circumferentially extending chambermeans therebetween; a rotatable shaft extending into said vessel throughsaid dish-shaped elements and adapted to be driven from a power source;agitator disc means mounted on said shaft and projecting radially intosaid chamber means; and said agitator disc means is an integral discincluding a central body portion and integral radially extending bladeportions disposed on each side of and axially spaced from said centralbody portion and vane means formed in each of said blade portions. 4.Apparatus for dispersing solid particles held in agglomerated form andcarried in suspension by a liquid vehicle as a fluid mixture comprising:a mixing vessel having a fluid inlet at one end thereof and a fluidoutlet at the other end thereof, said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture under pressurethrough said mixing vessel to said outlet; said mixing vessel includingat least one annular dish-shaped element having a substantially radiallyextending base portion and a substantially axially extending flangeportion connected to said radially extending base portion and a closuremember covering said dish-shaped element to define with the latter anannular chamber; releasable means securing said dish-shaped element andsaid closure member in assembled relationship whereby said dish-shapedelement and closure member may be easily assembled and disassembled; arotatable shaft extending into said vessel; an agitator disc secured tosaid shaft and extending into said annular chamber, said agitator discbeing an integral disc including a central body portion and integralradially extending blade portions disposed on each side of and axiallyspaced from said central body portion and vane means formed in each ofsaid body portions; means defining completely circumferentiallyextending internal fluid passage means in both said base portion andsaid flange portion of said dish-shaped element for conductingtemperature control fluid therethrough; and fluid inlet and outlet meansto said internal fluid passage means.
 5. Apparatus for dispersing solidparticles held in agglomerated form and carried in suspension by aliquid vehicle as a fluid mixture comprising: a mixing vessel having afluid inlet at one end thereof and a fluid outlet at the other endthereof, said inlet being adapted to be operatively connected to meansfor introducing a fluid mixture into said inlet under pressure andmoving said fluid mixture through said mixing vessel to said outlet;said vessel comprising a plurality of annular dish-shaped elementsstacked one upon the other and closure means associated with saiddish-shaped elements enclosing said vessel at both ends; releasablemeans holding said dish-shaped elements and said closure means inassembled relationship; said dish-shaped elements in their assembledrelationship defining circumferentially extending chamber meanstherebetween; means defining separate completely circumferentiallyextending internal fluid cavities entirely within each of saiddish-shaped elements for conducting temperature control fluidtherethrough; communicating passage means in said dish-shaped elementsconnecting the internal cavities of each of said dish-shaped cavitieswith each other; a rotatable shaft extending into said vessel throughsaid dish-shaped elements and adapted to be driven from a power source;and agitator disc means mounted on said shaft and projecting radiallyinto said chamber means.
 6. The apparatus of claim 5 wherein, saidcommunicating passage means includes a continuous annular passageway inthe upper face of said dish-shaped element for communicating with inletports formed in the base of an adjacent dish-shaped element. 7.ApparatUs for dispersing solid particles held in agglomerated form andcarried in suspension by a liquid vehicle as a fluid mixture comprising:a mixing vessel having a fluid inlet at one end thereof and a fluidoutlet at the other end thereof, said inlet being adapted to beoperatively connected to means for introducing a fluid mixture into saidinlet under pressure and moving said fluid mixture through said mixingvessel to said outlet; said vessel comprising a plurality of annulardish-shaped elements stacked one upon the other and closure meansassociated with said dish-shaped elements enclosing said vessel at bothends; releasable means holding said dish-shaped elements and saidclosure means in assembled relationship; said dish shaped elements intheir assembled relationship defining circumferentially extendingchamber means therebetween; means defining separate completelycircumferentially extending internal fluid cavities entirely within eachof said dish-shaped elements for conducting temperature control fluidtherethrough; a rotatable shaft extending into said vessel through saiddish-shaped elements and adapted to be driven from a power source;agitator disc means mounted on said shaft and projecting radially intosaid chamber means; and said agitator disc being an integral discincluding a central body portion and integral radially extending bladeportions disposed on each side of and axially spaced from said centralbody portion and vane means formed in each of said body portions.
 8. Ina closed mixing vessel apparatus for dispersing solid particles held inagglomerated form and carried in suspension by a liquid vehicle as afluid mixture, said mixing vessel having a chamber in which an agitatordisc adapted to be rotated is disposed, the combination comprising: anintegral agitator disc including a central body portion, and integralradially extending blade portions disposed on each side of and axiallyspaced from said central body portion and at the outer periphery of saiddisc; and vane means formed in each of said blade portions.
 9. Thecombination of claim 8 wherein, said agitator disc member is ofsubstantial thickness being formed with top and bottom faces andincludes means defining a pair of radially directed circumferentiallyextending slots disposed in substantially parallel relationship andformed in the periphery of said agitator disc, said slot means definingsaid blade portions at the outer edge of and as an integral part of saidtop and bottom faces, said slot means further defining said central bodyportion disposed between and axially spaced from said blade portions.